Transmission apparatus and transmission method of an aggregate physical layer protocol data unit

ABSTRACT

A transmission apparatus includes a transmission signal generator which, in operation, generates a transmission signal having an aggregate physical layer protocol data unit (PPDU) that includes a legacy preamble, a legacy header, a non-legacy preamble, a plurality of non-legacy headers and a plurality of data fields; and a transmitter which, in operation, transmits the generated transmission signal, wherein the legacy preamble, the legacy header and the plurality of non-legacy headers are transmitted using a standard bandwidth, the non-legacy preamble and the plurality of data fields are transmitted using a variable bandwidth that is larger than the standard bandwidth and wherein a plurality of sets of each of the plurality of non-legacy headers and each of the plurality of data fields are transmitted sequentially in a time domain.

BACKGROUND 1. Technical Field

The present disclosure generally pertains to wireless communicationsand, more particularly, to a method for formatting and transmitting anaggregate physical layer protocol data unit (PPDU) in a wirelesscommunications system.

2. Description of the Related Art

Interest in unlicensed 60 GHz millimeter wave (mmW) networks isincreasing. wireless Hi-Definition (HD) technology is the first 60 GHzmmW industry standard, which enables multi-gigabit wireless streaming ofhigh-definition audio, video and data among consumer electronics,personal computer and portable products. Another multi-gigabit wirelesscommunications technology operating over the 60 GHz mmW frequency bandis WiGig technology, which has been standardized by the Institute ofElectrical and Electronic Engineers (IEEE) as the IEEE 802.11ad standard(see IEEE 802.11ad-2012).

The WiGig technology supplements and extends the IEEE 802.11 mediaaccess control (MAC) layer and is backward compatible with the IEEE802.11 wireless local area network (WLAN) standard. The WiGig MACsupports a centralized network architecture such as an infrastructurebasic service set (BSS) or a personal BSS (PBSS), where only the centralcoordinator, e.g., an access point (AP) or personal BSS control point(PCP), transmits beacons to synchronize all stations (STAs) in thenetwork. Rather than other IEEE 802.11 WLAN technologies operating over2.4 GHz or 5 GHz frequency band, the WiGig technology makes extensiveuse of BF (beamforming) to achieve directional transmissions.

Due to a standard bandwidth of 2.16 GHz, the WiGig technology is able tooffer a physical layer (PHY) data rate of up to 6.7 Gbps. The WiGig PHYsupports both single carrier (SC) modulation and orthogonal frequencydivision multiplexing (OFDM) modulation. For the purpose of increasingtransmission efficiency, the WiGig PHY also supports “aggregate PPDU”.In the context of SC modulation, the aggregate PPDU is a sequence of twoor more SC PPDUs transmitted without inter-frame spacing (IFS), preambleand separation between PPDU transmissions.

A prevailing application of the WiGig technology is a cable replacementfor wired digital interface. For example, the WiGig technology can beused to implement a wireless Universal Serial Bus (USB) link for instantsynchronization between smart phones or tablets or a wirelessHigh-Definition Multimedia Interface (HDMI) link for video streaming.The state-of-the-art wired digital interfaces (e.g., USB 3.5 and HDMI1.3) enable data rates up to tens of Gbps and therefore the WiGigtechnology also needs to be evolved to match them. Techniques forsupporting multiple input multiple output (MIMO) transmission withvariable bandwidth while maintaining backward compatibility withexisting (i.e., legacy) WiGig devices would be desirable for NextGeneration 60 GHz (NG60) WiGig to achieve PHY data rates up to tens ofGbps.

In order to keep backward compatibility with legacy WiGig devices, theNG60 WiGig shall be able to support both legacy format (LF) PPDUs,defined in IEEE 802.11ad, with a standard bandwidth, and mixed format(MF) PPDUs with capability of accommodating MIMO transmission withvariable bandwidth. A non-limiting embodiment contributes to providing atransmission format and a transmission method of aggregate MF PPDU in anefficient way such that transmission efficiency can be maximized.

SUMMARY

In one general aspect, the techniques disclosed here feature: atransmission apparatus including a transmission signal generator which,in operation, generates a transmission signal having an aggregatephysical layer protocol data unit (aggregate PPDU) that includes alegacy preamble, a legacy header, a non-legacy preamble, a plurality ofnon-legacy headers and a plurality of data fields; and a transmitterwhich, in operation, transmits the generated transmission signal,wherein the legacy preamble, the legacy header and the plurality ofnon-legacy headers are transmitted using a standard bandwidth, thenon-legacy preamble and the plurality of data fields are transmittedusing a variable bandwidth that is the same as or greater than thestandard bandwidth, and a plurality of sets of each of the plurality ofnon-legacy headers and each of the plurality of data fields aretransmitted sequentially in a time domain.

With the transmission apparatus and transmission method of aggregate MFPPDU of the present disclosure, transmission efficiency is maximized.

It should be noted that general or specific embodiments may beimplemented as a system, a method, an integrated circuit, a computerprogram, a storage medium, or any selective combination thereof.

Additional benefits and advantages of the disclosed embodiments willbecome apparent from the specification and drawings. The benefits and/oradvantages may be individually obtained by the various embodiments andfeatures of the specification and drawings, which need not all beprovided in order to obtain one or more of such benefits and/oradvantages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating the format of an example SC PPDUaccording to the related art;

FIG. 2 is a diagram illustrating the fields of an example headeraccording to the related art;

FIG. 3 is a block diagram illustrating an example transmitter for theheader and the data field according to the related art;

FIG. 4 is a diagram illustrating the format of an example aggregate SCPPDU according to the related art;

FIG. 5 is a diagram illustrating the format of an example MF SC PPDUaccording to the present disclosure;

FIG. 6 is a diagram illustrating the content of an example NG60 headeraccording to the present disclosure;

FIG. 7 is a block diagram illustrating an example Tx baseband processorfor the NG60 header and the data field of the MF SC PPDU according tothe present disclosure;

FIG. 8 is a diagram illustrating transmission of the example MF SC PPDUin a channel where channel bandwidth is two times of standard bandwidthaccording to the present disclosure;

FIG. 9 is a block diagram illustrating an example Rx baseband processorfor receiving the MF SC PPDU according to the present disclosure;

FIG. 10A illustrates the format of an example aggregate MF SC PPDUaccording to a first embodiment of the present disclosure;

FIG. 10B illustrates the format of an example aggregate MF SC PPDUaccording to the first embodiment of the present disclosure;

FIG. 11 is a diagram illustrating transmission of the example aggregateMF SC PPDU in a channel where channel bandwidth is two times of standardbandwidth according to the first embodiment of the present disclosure;

FIG. 12 illustrates the format of an example aggregate MF SC PPDUaccording to a second embodiment of the present disclosure;

FIG. 13 is a diagram illustrating transmission of the example aggregateMF SC PPDU in a channel where channel bandwidth is two times of standardbandwidth according to the second embodiment of the present disclosure;

FIG. 14 illustrates the format of an example aggregate MF SC PPDUaccording to a third embodiment of the present disclosure;

FIG. 15 is a block diagram illustrating example architecture of awireless communication apparatus according to the present disclosure;

FIG. 16 is a diagram illustrating the format of an example componentaggregate MF SC PPDU where a plurality of aggregate MF SC PPDUs havefurther been aggregated, according to the first embodiment; and

FIG. 17 is a diagram illustrating transmission of an example componentaggregate MF SC PPDU where a plurality of aggregate MF SC PPDUs havefurther been aggregated, on a channel where the channel bandwidth is twotimes the standard bandwidth, according to the first embodiment.

DETAILED DESCRIPTION

Various embodiments of the present disclosure will now be described indetail with reference to the annexed drawings. In the followingdescription, a detailed description of known functions andconfigurations incorporate herein has been omitted for clarity andconciseness.

FIG. 1 illustrates the format of an example SC PPDU 100 according to therelated art. The SC PPDU 100 includes a short training field (STF) 101,a channel estimation field (CEF) 103, a header 112, a data field 114 andoptional AGC&TRN-R/T subfields 115. All the fields of the SC PPDU 100are transmitted with a standard bandwidth of 2.16 GHz.

The STF 101 is used for packet detection, automatic gain control (AGC),frequency offset estimation and synchronization. The CEF 103 is used forchannel estimation as well as indication of which of SC and OFDMmodulations is going to be used for the SC PPDU 100. The header 112includes a plurality of fields that define the details of the SC PPDU100 to be transmitted, as illustrated in FIG. 2.

The data field 114 includes the payload data of the SC PPDU 100. Thenumber of data octets in the data field 114 is specified by the Lengthfield of the header 112, and the MCS (Modulation and Coding Scheme) usedby the data field 114 is specified by the MCS field of the header 112.

The AGC&TRN-R/T subfields 115 are present only when the PPDU 100 is usedfor the purpose of beam refinement or tracking. The length ofAGC&TRN-R/T subfields 115 is specified by the Training Length field ofthe header 112. Whether TRN-R field or TRN-T field is present isspecified by the Packet Type field of the header 112.

FIG. 3 is a block diagram illustrating an example transmitter 300 forthe header 112 and the data field 114 according to the related art. Thetransmitter 300 includes a scrambler 302, a low density parity check(LDPC) encoder 304, a modulator 306 and a symbol blocking and guardInsertion block 308. The scrambler 302 scrambles the bits of the header112 and the data field 114. Note that a shift register included in thescrambler 302 is initialized according to the scrambler Initializationfield of the header 112. The header 112 is scrambled starting from thebits of the MCS field following the scrambler Initialization field.

In the context of the header 112, the LDPC encoder 304 performs LDPCencoding on the scrambled bits of the header 112 according to apredetermined code rate and generates a sequence of coded bits. Themodulator 306 converts the sequence of coded bits into a plurality ofcomplex constellation points using π/2 binary phase shift keying (BPSK).The symbol blocking and guard Insertion block 308 generates two SCblocks from the plurality of complex constellation points. Each SC block(e.g., 132) includes 448 π/2-BPSK data symbols and is prepended by aguard interval 131 of 64 π/2-BPSK symbols generated from the predefinedGolay sequence of length 64.

In the context of the data field 114, the LDPC encoder 304 performs LDPCencoding on the scrambled bits of the data field 114 according to a coderate which is specified by the MCS field of the header 112. The LDPCencoder 304 generates a sequence of coded bits, followed by padding bitsif necessary. The modulator 306 converts the coded and padded bit streaminto a stream of complex constellation points according to themodulation scheme specified by the MCS field of the header 112. Thesymbol blocking and guard Insertion block 308 generates a plurality ofSC blocks from the stream of complex constellation points. Each SC block(e.g., 142) includes 448 data symbols and is prepended by the same guardinterval 131. Furthermore, the final SC block 144 transmitted needs tobe followed by the same guard interval 131 for ease of SC frequencydomain equalization (FDE).

FIG. 4 illustrates the format of an example aggregate SC PPDU 400according to the related art. The aggregate PPDU 400 includes fourconstituent SC PPDUs. Each of the four PPDUs in the aggregate SC PPDU400 includes a header and a data field. For example, the PPDU 410includes a header 412 and a data field 414. In addition, the PPDU 410which is located at the beginning of the aggregate SC PPDU 400 includesthe STF 401 and the CEF 403 as well. And the SC PPDU 440 which islocated at the end of the aggregate SC PPDU 400 includes optional AGC &TRN-R/T subfields 445 as well. Notice that there are no IFS, preambleand separation between PPDU transmissions in the aggregate SC PPDU 400.

According to the related art, the STF 401, the CEF 403, each of theheaders (e.g., 412), each of the data fields (e.g., 414) and theAGC&TRN-T/R subfield 445 in the aggregate SC PPDU 400 are defined in theexactly same manner as their respective counterparts in the SC PPDU 100in FIG. 1.

According to the related art, the final SC block transmitted as a datafield, except the last data field 444, is followed by the first SC blocktransmitted as a header. So, only the final SC block 452 within the lastSC PPDU 440 needs to be post-pended by the same guard interval 131.

FIG. 5 illustrates the format of an example of MF SC PPDU 500 accordingto the present disclosure. The MF PPDU 500 includes a legacy STF 501, alegacy CEF 503, a legacy header 505, a NG60 header 512, a NG60 STF 507,a plurality of NG60 CEFs 509, a data field 514 and optional AGC&TRN-R/Tsubfields 515.

The legacy STF 501, the legacy CEF 503 and the legacy header 505 aredefined in the exactly same manner as their respective counterparts inFIG. 1.

The NG60 header 512 defines the details of the MF SC PPDU 500 to betransmitted. The example fields of the NG60 header 512 are illustratedin FIG. 6. The data field 514 consists of the payload data of the MF SCPPDU 500. Space-time block coding (STBC) or MIMO spatial multiplexingmay be applied to the data field 514, which results in a plurality ofspace-time streams (STSs) in the data field 514. The number of STSs inthe data field 514 is specified in the N_(sts) field of the NG60 header512.

The NG60 STF 507 is used for retraining AGC only. The plurality of NG60CEFs 509 is used for channel estimation for the plurality of STSs in thedata field 514. Note that the number of NG60 CEFs 509 depends on thenumber of STSs in the data field 514. In one embodiment, the number ofNG60 CEFs 509 shall not be smaller than the number of STSs in the datafield 514. For example, if the number of STSs in the data field 514 is2, the number of NG60 CEFs 509 can be set to 2. If the number of STSs inthe data field 514 is 3, the number of NG60 CEFs 509 can be set to 4.

FIG. 7 is a block diagram illustrating an example Tx baseband processor700 for the NG60 header 512 and the data field 514 of the MF SC PPDU500. The Tx baseband processor 700 includes a scrambler 702, a LDPCencoder 704, a modulator 706, a MIMO encoder 708 and a symbol blockingand guard Insertion block 710. The modulator 706 includes a firstmodulation functional block 712, a second modulation functional block714 and a third modulation functional block 716.

The bits of the NG60 header 512 are prepended to the bits of the datafield 514 and passed into the scrambler 702. The scrambler 702 scramblesthe bits of the NG60 header 512 and the data field 514 according to apredefined scrambling rule. Note that the shift register included in thescrambler 702 is initialized according to the scrambler Initializationfield in the NG60 header 512. The NG60 header 512 is scrambled startingfrom the bits of the MCS field following the scrambler Initializationfield, and the scrambling of the data field 514 follows the scramblingof the NG60 header 512 with no reset.

In the context of the NG60 header 512, the LDPC encoder 704 performsLDPC encoding on the scrambled bits of the NG60 header 512 according toa predetermined code rate and generates a sequence of coded bits. Thesecond modulation functional block 714 inside the modulator 706 convertsthe sequence of coded bits into a stream of complex constellation pointsusing π/2-BPSK with a phase rotation of 90 degrees. The symbol blockingand guard Insertion block 710 generates two SC blocks from the stream ofcomplex constellation points. Each SC block includes 448 data symbolsand is prepended by the same guard interval 131. In addition, the finalSC block 532 within the NG60 header 512 needs to be followed by the sameguard interval 131.

In the context of the data field 514, the LDPC encoder 704 performs LDPCencoding on the scrambled bits of the data field 514 according to a coderate which is specified by the MCS field of the NG60 header 512 andgenerates a sequence of coded bits, followed by padding bits ifnecessary. The third modulation functional block 716 in the modulator706 converts the coded and padded bit stream into a stream of complexconstellation points according to the modulation scheme specified by theMCS field of the NG60 header 512. Notice that the first modulationfunctional block 712 inside the modulator 706 is used for the modulationof the legacy header 505. Which one of the first modulation functionalblock 712, the second modulation functional block 714 and the thirdmodulation functional block 716 inside the modulator 706 is used isdetermined according to a control signal generated by the controller1502 as illustrated in FIG. 15. The MIMO encoder 708 applies the MIMOencoding to the stream of complex constellation points and obtains aplurality of STSs 550. For each STS, the symbol blocking and guardInsertion block 710 generates a plurality of SC blocks. The number of SCblocks per STS is the same. Each SC block (e.g., 542) includes N₁ datasymbols and is prepended by a guard interval 541 of N₂ π/2-BPSK symbolsgenerated from the predefined Golay sequence of length N₂, where N₁ andN₂ are positive integers and N₁ should be an integer multiple of N₂. Thevalues of N₁ and N₂ may be configurable and indicated in the NG60 header512. Furthermore, for each STS, the final SC block transmitted needs tobe followed by the same guard interval 541.

According to the present disclosure, since the legacy header 505 of theMF SC PPDU 500 has the exactly same format and Tx processing as theheader 112 of the SC PPDU 100, a legacy WiGig device is able to decodethe legacy header 505 of the MF SC PPDU 500 correctly.

According to the present disclosure, the NG60 header 512 of the MF SCPPDU 500 is modulated using π/2-BPSK with a phase rotation of 90degrees, which is different from a phase rotation of the legacy header505. Due to such modulation difference, a NG60 device is able todetermine whether the received SC PPDU is MF or LF.

According to the present disclosure, a legacy WiGig device would processthe received MF SC PPDU 500 in the same manner as the SC PPDU 100. Inother words, the legacy WiGig device would envision the NG60 header 512,the NG60 STF 507 and the NG60 CEFs 509 as a part of the PHY service dataunit (PSDU). In order for the legacy WiGig device to determine theactual transmission time of the PSDU correctly, the values of the MCSfield and the Length field of the legacy header 505 shall beappropriately set.

According to the present disclosure, a NG60 device is able to know thechannel bandwidth information only after it successfully decodes theNG60 header 512. As a result, the NG60 STF 507, the plurality of NG60CEFs 509, the data field 514 and the optional AGC&TRN-R/T subfields 515can be transmitted with variable bandwidth. However, the legacy STF 501,the legacy CEF 503, the legacy header 505 and the NG60 header 512 can betransmitted with standard bandwidth only. In a channel with a channelbandwidth of M multiples of standard bandwidth, M copies of the legacySTF 501, the legacy CEF 503, the legacy header 505 and the NG60 header512 can be transmitted with standard bandwidth in the channelsimultaneously after an appropriate frequency offset is applied to eachof these M copies. FIG. 8 is a diagram illustrating transmission of theMF SC PPDU 500 in a channel where channel bandwidth is two times ofstandard bandwidth. As shown in FIG. 8, the frequency offset for theoriginal legacy STF, legacy CEF, legacy header and NG60 header can beset to 50% of standard bandwidth and the frequency offset for theduplicated legacy STF, legacy CEF, legacy header and NG60 header can beset to −50% of standard bandwidth.

FIG. 9 is a block diagram illustrating an example Rx baseband processor900 for receiving the MF SC PPDU 500 according to the presentdisclosure. The Rx baseband processor 900 includes a symbol unblockingand guard removal block 902, a MIMO decoder 904, a demodulator 906, aLDPC decoder 908, a descrambler 910 and a channel estimator 912. Notethat the MIMO Decoder 904 is only applicable to decoding of the datafield 514.

The symbol unblocking and guard removal block 902 performs the inversionoperation with respect to the symbol blocking and guard insertion block710 on the received SC MF PPDU 500.

The NG60 header 512 needs to be decoded first. For this purpose, thedemodulator 906 performs the inversion operation with respect to themodulator 706 based on the channel estimates obtained by the channelestimator 912 from the legacy CEF 503. In more details, the seconddemodulation functional block 916 is applied to the portioncorresponding to the NG60 header 512. After that the LDPC Decoder 908and the descrambler 910 perform the inversion operation with respect tothe LDPC encoder 704 and the scrambler 702, respectively, resulting inthe decoded bits of the legacy header 505 and the NG60 header 512.

After decoding the NG60 header 512, the Rx baseband processor 900proceeds to decode the data field 514 based on the information of theNG60 header 512. The MIMO Decoder 904 performs the inversion operationwith respect to the MIMO encoder 708 on the portion of the received MFSC PPDU 500 corresponding to the data field 514 based on the channelestimates obtained by the channel estimator 912 from the NG60 CEFs 509.The demodulator 906 performs the inversion operation with respect to themodulator 706. In more details, the third demodulation functional block918 is applied to the portion corresponding to the data field 514.Notice that the first demodulation functional block 914 inside thedemodulator 906 is used for the demodulation of the received legacyheader 505. Which one of the first demodulation functional block 914,the second demodulation functional block 916 and the third demodulationfunctional block 918 is used is determined according to a control signalgenerated by the controller 1502 as shown in FIG. 15. After that theLDPC Decoder 908 and the descrambler 910 perform the inversion operationwith respect to the LDPC encoder 704 and the scrambler 702,respectively, resulting in the decoded bits of the data field 514.

First Embodiment

FIGS. 10a and 10b illustrate a format of an example of an aggregate MFSC PPDU 1000 according to a first embodiment of the present disclosure.The aggregate MF SC PPDU 1000 includes four MF SC PPDUs. Each of thefour MF SC PPDUs includes a NG60 header and a data field. For example,the first MF SC PPDU 1010 includes a NG60 header 1012 and a data field1014. The first MF SC PPDU 1010 which is located at the beginning of theaggregate MF SC PPDU 1000 further includes a legacy STF 1001, a legacyCEF 1003, a legacy header 1005, a NG60 STF 1007 and a plurality of NG60CEFs 1009. The second MF SC PPDU 1020 which is located next to the firstMF SC PPDU 1010 includes a NG60 header 1022 and a data field 1024. Thelast MF SC PPDU 1040 which is located at the end of the aggregate MF SCPPDU 1000 further includes optional AGC & TRN-R/T subfields 1045. Noticethat there are no IFS, preamble and separation between MF PPDUtransmissions in the aggregate MF SC PPDU 1000. So compared withindividual transmission of normal MF SC PPDUs 500, transmissionefficiency is improved.

According to the first embodiment of the present disclosure, all of thedata fields in the aggregate MF SC PPDU 1000 have the same transmissionbandwidth. In one embodiment, the number of STSs N_(sts) for the datafields in the aggregate MF SC PPDU 1000 may be different. For example,as shown in FIG. 10A, each of the data field 1014 and the data field1044 has two STSs, while the data field 1024 has a single STS and thedata field 1034 has three STSs. In this case, the number of NG60 CEFs1009 depends on the maximum number of STSs among all of the data fieldsin the aggregate MF SC PPDU 1000. For example, if the maximum number ofSTSs among all of the data fields is 2, the number of NG60 CEFs 1009 canbe set to 2. If the maximum number of STSs among all of the data fieldsis 3, the number of NG60 CEFs 1009 can be set to 4. In anotherembodiment, the number of STSs N_(sts) for the data fields in theaggregate MF SC PPDU 1000 may be the same. For example, as shown in FIG.10B, each of the data fields has two STSs.

According to the first embodiment of the present disclosure, the NG60STF 1007, the plurality of NG60 CEFs 1009, each of the data fields(e.g., 1014) and the optional AGC & TRN-R/T subfields 1045 can betransmitted with variable bandwidth. However, the legacy STF 1001, thelegacy CEF 1003, the legacy header 1005 and each of the NG60 headers(e.g., 1012) can be transmitted with standard bandwidth only. FIG. 11 isa diagram illustrating transmission of the aggregated MF SC PPDU 1000 ina channel where channel bandwidth is two times of standard bandwidth. Asshown in FIG. 11, each of the original legacy STF, the original legacyCEF, the original legacy header and all of the original NG60 headers areduplicated in a frequency domain. Here, the frequency offset for theoriginal legacy STF, the original legacy CEF, the original legacy headerand all of the original NG60 headers can be set to 50% of the standardbandwidth. And the frequency offset for the duplicated legacy STF, theduplicated legacy CEF, the duplicated legacy header and all of theduplicated NG60 headers can be set to −50% of the standard bandwidth.

According to the first embodiment of the present disclosure, for all ofthe data fields in the aggregate MF SC PPDU 1000, each SC block includesthe same number of data symbols and is prepended by the same guardinterval 1051.

According to the first embodiment of the present disclosure, since aNG60 header may have a transmission bandwidth different from atransmission bandwidth of its following data field, the final SC blocktransmitted as every NG60 header in the aggregate MF SC PPDU 1000 needsto be followed by the same guard interval 131. Consequently, the numberof required post-pended guard intervals for the NG60 headers is 4. Thefinal SC block per STS transmitted of every data field in the aggregateMF SC PPDU 1000 needs to be followed by the same guard interval 1051.Consequently, the number of required post-pended guard intervals for thedata fields is 8.

According to the first embodiment of the present disclosure, the Txbaseband processor 700 for transmitting the MF SC PPDU 500 can be easilyadapted for transmitting the aggregate MF SC PPDU 1000. Similarly, theRx baseband processor 900 for receiving the MF SC PPDU 500 can be easilyadapted for receiving the aggregated MF SC PPDU 1000. Notice that thechannel estimates obtained by the channel estimator 912 from the legacyCEF 1003 can be used for decoding all of the NG60 headers 1012, 1022,1032 and 1042 in the received aggregate MF SC PPDU 1000.

The channel estimates obtained by the channel estimator 912 from theNG60 CEFs 1009 can be used for decoding all of the data fields 1014,1024, 1034 and 1044 in the received aggregate MF SC PPDU 1000. As aresult, compared with individual transmission and reception of normal MFPPDUs 500, transmission and reception of the aggregate MF SC PPDU 1000does not incur extra implementation complexity.

According to the first embodiment of the present disclosure, a legacySTA is able to decode the legacy header 1005 but cannot decode theremaining of the aggregate MF SC PPDU 1000. In order for the legacy STAto estimate transmission time of the aggregated MF SC PPDU 1000correctly to avoid packet collision, the additional PPDU field in thelegacy header 1016 shall be set to 0. In other words, the aggregate MFSC PPDU 1000 shall be envisioned by the legacy STA as a normal legacyPPDU 100 instead of legacy aggregate SC PPDU 400. In addition, the MCSfield and the Length field in the legacy header 1005 shall beappropriately set so that the transmission time calculated by the legacySTA is the same as the actual transmission time of the equivalent datafield, which includes the NG60 STF 1007, the NG60 CEFs 1009, all of theNG60 headers and all of the data fields in the aggregate MF SC PPDU1000. In other words, a total packet length of the NG60 STF 1007, theNG60 CEFs 1009, all of the NG60 headers and all of the data fields isset as the Length field in the legacy header 1005.

According to the first embodiment of the present disclosure, a legacySTA is able to calculate the actual transmission time of the equivalentdata field of the aggregate MF SC PPDU 1000, by decoding the legacyheader 1005. Accordingly, in a case where the clock frequency errorbetween the central coordinator such as an access point or PCP and alegacy STA is extremely small, the additional PPDU field in the legacyheader 1005 can be set to 1.

FIG. 16 is a diagram illustrating the format of aggregate MF SC PPDU1600 where a plurality of (e.g., two) component aggregate MF SC PPDUs ofwhich the data fields all have the same transmission bandwidth, havebeen linked. As illustrated in FIG. 16, the aggregate MF SC PPDU 1600includes a first component aggregate MF SC PPDU 1610 located at thebeginning, and a second component aggregate MF SC PPDU 1620 located atthe end. The first component aggregate MF SC PPDU 1610 includes a firstMF SC PPDU 1610-1 located at the beginning, and a second MF SC PPDU1610-2 located at the end. The second component aggregate MF SC PPDU1620 includes a third MF SC PPDU 1620-1 located at the beginning, and afourth MF SC PPDU 1620-2 located at the end. Each of the MF SC PPDUs1610-1, 1610-2, 1620-1, and 1620-2 includes an NG60 header and datafield. For example, the first MF SC PPDU 1610-1 includes an NG60 header1612 and data field 1614. The first MF SC PPDU 1610-1 further includes alegacy STF 1601, legacy CEF 1603, legacy header 1605, NG60 STF 1607, anda plurality of NG60 CEFs 1609. The third MF SC PPDU 1620-1 furtherincludes a legacy header 1635, an NG60 STF 1637, and a plurality of NG60CEFs 1639. The fourth MF SC PPDU 1620-2 further includes optionalAGC&TRN-R/T subfields 1645. Notice that there are no IFS, preamble andseparation between component aggregate MF SC PPDU transmissions in theaggregate MF SC PPDU 1600.

FIG. 17 is a diagram illustrating transmission of the aggregate MF SCPPDU 1600 on a channel where the channel bandwidth is two times thestandard bandwidth. The original legacy STF, original legacy CEF,original legacy header, and original NG60 header are each duplicated inthe frequency region, as illustrated in FIG. 17. Accordingly, thefrequency offset as to the original legacy STF, original legacy CEF,original legacy header, and all original NG60 headers, can be set to 50%of the standard bandwidth. Further, the frequency offset as to theduplicated legacy STF, duplicated legacy CEF, duplicated legacy header,and all duplicated NG60 headers, can be set to −50% of the standardbandwidth.

The ideas and concepts disclosed in this embodiment can be implementedfor formatting and transmission of MF OFDM PPDUs.

Second Embodiment

FIG. 12 illustrates the format of another example of an aggregate MF SCPPDU 1200 according to a second embodiment of the present disclosure.The aggregate SC PPDU 1200 includes four MF SC PPDUs 1210, 1220, 1230and 1240. Each of the four MF SC PPDUs includes a NG60 header and a datafield. For example, the MF SC PPDU 1210 includes a NG60 header 1212 anda data field 1214. The first MF SC PPDU 1210 which is located at thebeginning of the aggregate MF SC PPDU 1200 further includes a legacy STF1201, a legacy CEF 1203, a legacy header 1205, a NG60 STF 1207 and aplurality of NG60 CEFs 1209. The last SC MF SC PPDU 1240 which islocated at the end of the aggregate MF SC PPDU 1200 further includesoptional AGC&TRN-R/T subfields 1245. Notice that there are no IFS,preamble and separation between MF SC PPDU transmissions in theaggregate MF SC PPDU 1200. So compared with individual transmission ofnormal MF SC PPDUs 500, transmission efficiency is improved.

According to the second embodiment of the present disclosure, besidesthe same transmission bandwidth, all of the data fields in the aggregateMF SC PPDU 1200 have the same number of STSs. For example, as shown inFIG. 12, every data field in the aggregate MF SC PPDU 1200 has two STSs.

According to the second embodiment of the present disclosure, for all ofthe data fields in the aggregate MF SC PPDU 1200, each SC block includesthe same number of data symbols and is prepended by the same guardinterval 1251.

According to the second embodiment of the present disclosure, all of theNG60 headers are located together right before the NG60 STF 1207.Consequently, only the final SC block that is transmitted as the lastNG60 header 1242 in the aggregate MF SC PPDU 1200 needs to be followedby the same guard interval 131. In other words, the number of requiredpost-pended guard intervals for the NG60 headers is 1. In addition, allof the data fields are also located together right after the NG60 CEFs1209. Therefore, only the final SC block per STS transmitted in the lastdata field 1244 in the aggregate MF SC PPDU 1200 needs to be followed bythe same guard interval 1251 as the one preceding the last data field1244. In other words, the number of required post-pended guard intervalsfor the data fields is 2.

According to the second embodiment of the present disclosure, comparedwith the first embodiment, due to the less number of guard intervalsrequired, the transmission efficiency is further improved. Furthermore,since there is no need of changing the sampling rate so frequently, Txand Rx processing is simplified and implementation complexity is furtherimproved.

According to the second embodiment of the present disclosure, the NG60STF 1207, the plurality of NG60 CEFs 1209, each of the data fields(e.g., 1214) and the optional AGC & TRN-R/T subfields 1245 can betransmitted with a variable bandwidth. However, the legacy STF 1201, thelegacy CEF 1203, the legacy header 1205 and each of the NG60 headers(e.g., 1212) can be transmitted with the standard bandwidth only. FIG.13 is a diagram illustrating transmission of the aggregated MF SC PPDU1200 in a channel where its channel bandwidth is two times of standardbandwidth. As shown in FIG. 13, each of the original legacy STF, theoriginal legacy CEF, the original legacy header and all of the originalNG60 headers are duplicated in a frequency domain. Here, the frequencyoffset for the original legacy STF, the original legacy CEF, theoriginal legacy header and all of the original NG60 headers can be setto 50% of the standard bandwidth and the frequency offset for theduplicated legacy STF, the duplicated legacy CEF, the duplicated legacyheader and all of the duplicated NG60 headers can be set to −50% of thestandard bandwidth.

According to the second embodiment of the present disclosure, the Txbaseband processor 700 for transmitting the MF SC PPDU 500 can be easilyadapted for transmitting the aggregate MF SC PPDU 1200 because switchingof the transmission bandwidth is unnecessary. For the same reason, theRx baseband processor 900 for receiving the MF SC PPDU 500 can be easilyadapted for receiving the aggregated MF SC PPDU 1200. Notice that thechannel estimates obtained by the channel estimator 912 from the legacyCEF 1203 can be used for decoding all of the NG60 headers 1212, 1222,1232 and 1242 in the received aggregate MF SC PPDU 1200. The channelestimates obtained by the channel estimator 912 from the NG60 CEFs 1209can be used for decoding all of the data fields 1214, 1224, 1234 and1244 in the received aggregate MF SC PPDU 1200. In addition, due toseparation of a NG60 header and its corresponding data field, there is aneed for storing the useful information of all of the NG60 headers fordecoding all of the data fields. However, the required memory size maybe trivial since the useful information of a NG60 header is small (about7 bytes). As a result, compared with individual transmission andreception of normal MF SC PPDUs 500, transmission and reception of theaggregate MF SC PPDU 1200 does not increase implementation complexitysignificantly.

According to the second embodiment of the present disclosure, a legacySTA is able to decode the legacy header 1205 but cannot decode theremaining of the aggregate MF SC PPDU 1200. In order for the legacy STAto estimate transmission time of the aggregated MF SC PPDU 1200correctly to avoid packet collision, the additional PPDU field in thelegacy header 1205 shall be set to 0. In other words, the aggregate SCMF PPDU 1200 shall be envisioned by the legacy STA as a normal legacy SCPPDU 100 instead of legacy aggregate SC PPDU 400. In addition, the MCSfield and the Length field in the legacy header 1205 shall beappropriately set so that the transmission time calculated by the legacySTA is the same as the actual transmission time of the equivalent datafield, which includes the NG60 STF 1207, the NG60 CEFs 1209, all of theNG60 headers and all of the data fields in the aggregate MF vPPDU 1200.In other words, a total packet length of the NG60 STF 1207, the NG60CEFs 1209, all of the NG60 headers 1212, 1222, 1232 and 1242 and all ofthe data fields 1214, 1224, 1234 and 1244 is set as the Length field inthe legacy header 1205.

According to the second embodiment of the present disclosure, symbolsmay be inverted in the guard interval following the final SC block ofevery MF SC PPDU in the aggregate MF SC PPDU 1200. Inverting symbols canbe performed by replacing bit 0 and bit 1 with bit 1 and bit 0,respectively. Consequently, the receiver can easily determine theboundary between neighboring data fields so that it can decode a datafield even if some of NG60 headers preceding the NG60 headercorresponding to the data field are lost.

The ideas and concepts disclosed in this embodiment can be implementedfor formatting and transmission of MF OFDM PPDUs.

Third Embodiment

FIG. 14 illustrates the format of another example of aggregate MF SCPPDU 1400 according to a third embodiment of the present disclosure. Theaggregate MF SC PPDU 1400 includes four MF SC PPDUs 1410, 1420, 1430 and1440. Each of the four MF SC PPDUs includes a NG60 header and a datafield. For example, the MF SC PPDU 1410 includes a NG60 header 1412 anda data field 1414. The MF SC PPDU 1420 which is located at the beginningof the aggregate MF PPDU 1400 further includes a legacy STF 1401, alegacy CEF 1403, a legacy header 1405, a NG60 STF 1407, a plurality ofNG60 CEFs 1409 and a data field 1424. The MF SC PPDU 1430 which islocated at the end of the aggregate MF SC PPDU 1400 includes a NG60header 1432 and a data field 1434 and further includes optionalAGC&TRN-R/T subfields 1435. Notice that there are no IFS, preamble andseparation between MF SC PPDU transmissions in the aggregate MF SC PPDU1400. So compared with individual transmission of normal MF SC PPDUs,transmission efficiency is improved.

As is apparent from FIG. 14, all of the NG60 headers are locatedtogether right before the NG60 STF 1407. Consequently, only the final SCblock that is transmitted as the last NG60 header 1432 in the aggregateMF PPDU 1400 needs to be followed by the same guard interval 131. Inother words, the number of required post-pended guard intervals for theNG60 headers is 1. In addition, all of the data fields are also locatedtogether right after the NG60 CEFs 1409. Therefore, only the final SCblock per STS transmitted in the last data field 1434 in the aggregateMF SC PPDU 1400 needs to be followed by the same guard interval 1451 asthe one preceding the final SC block. The number of required post-pendedguard intervals for the data fields is 3 in FIG. 14.

According to the third embodiment of the present disclosure, all of thedata fields in the aggregate MF SC PPDU 1400 have the same transmissionbandwidth. However, other transmission parameters (e.g., the number ofSTSs N_(sts)) for the data fields in the aggregate MF SC PPDU 1400 maybe different. For example, as shown in FIG. 14, each of the data field1414 and the data field 1444 has two STSs, while the data field 1424 hasa single STS and the data field 1434 has three STSs. The number of NG60CEFs 1409 depends on the maximum number of STSs among all of the datafields in the aggregate MF SC PPDU 1400. For example, if the maximumnumber of STSs among all of the data fields is 2, the number of NG60CEFs 1409 can be set to 2. If the maximum number of STSs among all ofthe data fields is 3, the number of NG60 CEFs 1409 can be set to 4.

According to the third embodiment of the present disclosure, for all ofthe data fields in the aggregate MF SC PPDU 1400, each SC block includesthe same number of data symbols and is prepended by the same guardinterval 1451.

According to the third embodiment of the present disclosure, all of theNG60 headers are located together right before the NG60 STF 1407 inincreasing order of the number of STSs which their corresponding datafields have. For example, as shown in FIG. 14, the NG60 header 1422 islocated immediately after the legacy header 1405, followed by the NG60header 1412 and the NG60 header 1442 as well as the NG60 header 1432 inthis order. Alternatively, all of the NG60 headers are located togetherright before the NG60 STF 1407 in decreasing order of the number of STSswhich their corresponding data fields have. Notice that only the finalSC block transmitted of the NG60 header 1432 in the aggregate MF SC PPDU1400 needs to be followed by the same guard interval 131 as insertedbefore. In other words, the number of required post-pended guardintervals for the NG60 headers is 1.

According to the third embodiment of the present disclosure, all of thedata fields are located together right after the NG60 CEFs 1409 in thesame order as the NG60 headers. For example, as shown in FIG. 14, thedata field 1424 is located immediately after the NG60 CEFs 1409,followed by the data field 1414 and the data field 1444 as well as thedata field 1434. Based on such arrangement of the data fields, only thefinal SC block per STS transmitted of the last data field 1434 in theaggregate MF SC PPDU 1400 needs to be followed by the same guardinterval 1451. In other words, the number of required post-pended guardintervals is 3.

According to the third embodiment of the present disclosure, comparedwith the first embodiment, due to the less number of guard intervalsrequired, the transmission efficiency is further improved. Furthermore,since there is no need of changing the sampling rate so frequently,TX/RX processing is simplified and implementation complexity is furtherimproved.

According to the third embodiment of the present disclosure, the NG60STF 1407, the plurality of NG60 CEFs 1409, each of the data fields(e.g., 1414) and the optional AGC & TRN-R/T subfields 1435 can betransmitted with variable bandwidth. However, the legacy STF 1401, thelegacy CEF 1403, the legacy header 1405 and each of the NG60 headers(e.g., 1412) can be transmitted with standard bandwidth only. FIG. 13 isa diagram illustrating transmission of the aggregated MF SC PPDU 1400 ina channel where channel bandwidth is two times of standard bandwidth.

According to the third embodiment of the present disclosure, the Txbaseband processor 700 for transmitting the MF SC PPDU 500 can be easilyadapted for transmitting the aggregate MF SC PPDU 1400. Similarly, theRx baseband processor 900 for receiving the MF SC PPDU 500 can be easilyadapted for receiving the aggregated MF SC PPDU 1400. Notice that thechannel estimates obtained by the channel estimator 912 from the legacyCEF 1403 can be used for decoding all of the NG60 headers 1412, 1422,1432 and 1442 in the received aggregate MF SC PPDU 1400. The channelestimates obtained by the channel estimator 912 from the NG60 CEFs 1409can be used for decoding all of the data fields 1414, 1424, 1434 and1444 in the received aggregate MF SC PPDU 1400. In addition, due toseparation of a NG60 header and its corresponding data field, there is aneed for storing the useful information of all of the NG60 headers fordecoding all of the data fields. However, the required memory size maybe trivial since the useful information of a NG60 header is small (about7 bytes). As a result, compared with individual transmission andreception of normal MF SC PPDUs 500, transmission and reception of theaggregate MF SC PPDU 1400 does not increase implementation complexitysignificantly.

According to the third embodiment of the present disclosure, a legacySTA is able to decode the legacy header 1405 but cannot decode theremaining of the aggregate MF SC PPDU 1400. In order for the legacy STAto estimate transmission time of the aggregated MF SC PPDU 1400correctly to avoid packet collision, the additional PPDU field in thelegacy header 1405 shall be set to 0. In other words, the aggregate MFSC PPDU 1400 shall be envisioned by the legacy STA as a normal legacy SCPPDU 100 instead of legacy aggregate SC PPDU 400. In addition, the MCSfield and the Length field in the legacy header 1405 shall beappropriately set so that the transmission time calculated by the legacySTA is the same as the actual transmission time of the equivalent datafield, which includes the NG60 STF 1407, the NG60 CEFs 1409, all of theNG60 headers and all of the data fields in the aggregate MF SC PPDU1400. In other words, a total packet length of the NG60 STF 1407, theNG60 CEFs 1409, all of the NG60 headers 1412, 1422, 1432 and 1442 andall of the data fields 1414, 1424, 1434 and 1444 is set as the Lengthfield in the legacy header 1405.

According to the third embodiment of the present disclosure, symbols maybe inverted in the guard interval following immediately the final SCblock of every MF SC PPDU in the aggregate MF SC PPDU 1400. Invertingsymbols can be performed by replacing bit 0 and bit 1 with bit 1 and bit0, respectively. Consequently, the receiver can easily determine theboundary between neighboring data fields so that it can decode a datafield even if some of NG60 headers preceding the NG60 headercorresponding to the data field are lost.

The ideas and concepts disclosed in this embodiment can be implementedfor formatting and transmission of MF OFDM PPDUs.

FIG. 15 is a block diagram illustrating example architecture of awireless communication apparatus 1500 according to the presentdisclosure. The wireless communication apparatus 1500 includes acontroller 1502, a Tx processor 1510, a Rx processor 1520 and aplurality of antennas 1530. The controller 1502 is includes a PPDUgenerator 1504, which is configured to create PPDUs, e.g., MF PPDU oraggregate MF PPDU. The Tx processor 1510 includes a Tx basebandprocessor 1512 and a Tx RF frontend 1514. The Rx processor 1520 includesa Rx baseband processor 1522 and a Rx RF frontend 1524. The Tx basebandprocessor 1512 is illustrated in FIG. 7 and the Rx baseband processor1522 is illustrated in FIG. 9. The created PPDUs are transmitted throughthe antenna 1530 after transmitter processing by the Tx processor 1510.On the other hand, the controller 1502 is configured to analyze andprocess PPDUs which are received through the antenna 1530 after receiverprocessing by the Rx processor 1520.

Summarization of Embodiments

A transmission apparatus according to an aspect of the presentdisclosure includes: a transmission signal generator which, inoperation, generates a transmission signal having an aggregate physicallayer protocol data unit (aggregate PPDU) that includes a legacypreamble, a legacy header, a non-legacy preamble, a plurality ofnon-legacy headers, and a plurality of data fields; and a transmitterwhich, in operation, transmits the generated transmission signal,wherein the legacy preamble, the legacy header and the plurality ofnon-legacy headers are transmitted using a standard bandwidth, thenon-legacy preamble and the plurality of data fields are transmittedusing a variable bandwidth that is larger than the standard bandwidthand wherein a plurality of sets of each of the plurality of non-legacyheaders and each of the plurality of data fields are transmittedsequentially in a time domain.

The non-legacy preamble may include a non-legacy short training field(STF) and a plurality of non-legacy channel estimation fields (CEFs) inthis order, and one of the plurality of non-legacy headers is locatedright before the non-legacy STF and one of the plurality of data fieldsis located right after of the non-legacy CEFs; each of the plurality ofremaining non-legacy headers is located right before each of theplurality of remaining data fields.

A single carrier (SC) block or an orthogonal frequency divisionmultiplexing (OFDM) symbol, which is transmitted in each of theplurality of non-legacy headers may be pre-pended by a guard interval,and a final SC block transmitted in each of the plurality of non-legacyheaders is post-pended by a same guard interval as the pre-pended guardinterval.

A single carrier (SC) block or an orthogonal frequency divisionmultiplexing (OFDM) symbol, per space-time stream, which is transmittedin each of the plurality of data fields is pre-pended by a guardinterval, and a final SC block per space-time stream transmitted in eachof the plurality of data fields may be post-pended by a same guardinterval as the pre-pended guard interval.

The non-legacy preamble may include a non-legacy short training field(STF) and a plurality of non-legacy channel estimation fields (CEFs) inthis order. The plurality of non-legacy headers may be located beforethe non-legacy STF; the plurality of data fields are located after theplurality of non-legacy CEFs.

The plurality of sets may be located in a decreasing or in an increasingorder of a number of space-time streams of each of the plurality of datafields.

A single carrier (SC) block or an orthogonal frequency divisionmultiplexing (OFDM) symbol, which is transmitted in each of theplurality of non-legacy headers may be pre-pended by a guard interval.The final SC block transmitted in the last non-legacy header may bepost-pended by a same guard interval as the pre-pended guard interval.

A single carrier (SC) block or an orthogonal frequency divisionmultiplexing (OFDM) symbol, per space-time stream, which is transmittedin each of the plurality of data fields may be pre-pended by a guardinterval. A final SC block per space-time stream transmitted in each ofthe plurality of data fields may be post-pended by a same guard intervalas the pre-pended guard interval.

Symbols in the post-pended guard interval may be inverted.

A transmission method according to an aspect of the present disclosureincludes: generating a transmission signal having an aggregate physicallayer protocol data unit (aggregate PPDU) that includes a legacypreamble, a legacy header, a non-legacy preamble, a plurality ofnon-legacy headers, and a plurality of data fields; and transmitting thegenerated transmission signal, wherein the legacy preamble, the legacyheader and the plurality of non-legacy headers are transmitted using astandard bandwidth, the non-legacy preamble and the plurality of datafields are transmitted using a variable bandwidth that is larger thanthe standard bandwidth and wherein a plurality of sets each of theplurality of non-legacy headers and each of the plurality of data fieldsare transmitted sequentially in a time domain.

The non-legacy preamble may include a non-legacy short training field(STF) and a plurality of non-legacy channel estimation fields (CEFs) inthis order. One of the plurality of non-legacy headers may be locatedright before the non-legacy STF and one of the plurality of data fieldsis located right after of the non-legacy CEFs, each of the plurality ofremaining non-legacy headers is located right before each of theplurality of remaining data fields.

A single carrier (SC) block or an orthogonal frequency divisionmultiplexing (OFDM) symbol, which is transmitted in each of theplurality of non-legacy headers may be pre-pended by a guard interval. Afinal SC block transmitted in each of the plurality of non-legacyheaders may be post-pended by a same guard interval as the pre-pendedguard interval.

A single carrier (SC) block or an orthogonal frequency divisionmultiplexing (OFDM) symbol, per space-time stream, which is transmittedin each of the plurality of data fields may be pre-pended by a guardinterval. A final SC block per space-time stream transmitted in each ofthe plurality of data fields may be post-pended by a same guard intervalas the pre-pended guard interval.

The non-legacy preamble may include a non-legacy short training field(STF) and a plurality of non-legacy channel estimation fields (CEFs) inthis order. The plurality of non-legacy headers may be located beforethe non-legacy STF; the plurality of data fields are located after theplurality of non-legacy CEFs.

The plurality of sets may be located in a decreasing or in an increasingorder of a number of space-time streams of each of the plurality of datafields.

A single carrier (SC) block or an orthogonal frequency divisionmultiplexing (OFDM) symbol, which is transmitted in each of theplurality of non-legacy headers is pre-pended by a guard interval, andthe final SC block transmitted in the last non-legacy header may bepost-pended by a same guard interval as the pre-pended guard interval.

A single carrier (SC) block or an orthogonal frequency divisionmultiplexing (OFDM) symbol, per space-time stream, which is transmittedin each of the plurality of data fields is pre-pended by a guardinterval, and a final SC block per space-time stream transmitted in eachof the plurality of data fields may be post-pended by a same guardinterval as the pre-pended guard interval.

Symbols in the post-pended guard interval may be inverted.

While the embodiments have been described with reference to thedrawings, it is needless to say that the present description is notrestricted to these examples. It is obvious that one skilled in the artwould be able to reach various modifications and alterations withoutdeparting from the scope of the Claims, and that such modifications andalterations belong to the technical scope of the present disclosure as amatter of course. The components in the above-described embodiments mayalso be optionally combined without departing from the scope of thepresent disclosure.

While the above embodiments have been described exemplifying examples ofconfiguring the disclosure using hardware, the present disclosure may berealized by software in conjunction with hardware.

The functional blocks used in the description of the embodiments abovemay be realized as a large-scale integration (LSI) that is an integratedcircuit (IC) having input terminals and output terminals. These may eachbe independently formed as single chips, or part or all may be includedin a single chip. While an LSI has been described, there are differentnames according to the degree of integration, such as IC, system LSI,super LSI, and ultra LSI.

The way in which the integrated circuit is formed is not restricted toLSIs, and may be realized by dedicated circuits or general-purposeprocessors. A field programmable gate array (FPGA) capable of beingprogrammed after manufacturing the LSI, or a reconfigurable processor ofwhich the connections and settings of circuit cells within the LSI canbe reconfigured, may be used.

Moreover, in the event of the advent of an integrated circuit technologywhich would replace LSIs by advance of semiconductor technology or aseparate technology derived therefrom, such a technology may be used forintegration of the functional blocks, as a matter of course. Applicationof biotechnology is a possibility.

This disclosure can be applied to a method for formatting andtransmitting an aggregate PPDU in a wireless communications system.

What is claimed is:
 1. A reception apparatus comprising: a receiver which, in operation, receives, from a transmission apparatus, a transmission signal having an aggregate physical layer protocol data unit (aggregate PPDU) that includes a first set and one or more second sets, the first set including a plurality of first fields arranged in order of a legacy preamble field, a legacy header field, a non-legacy header field, a non-legacy preamble field, and a data field on a time axis, each of the one or more second sets including a plurality of second fields arranged in order of the non-legacy header field and the data field on the time axis; and a decoder which, in operation, decodes the transmission signal to generate decoded bits for the data field in the first set and the data field in the plurality of second sets by using the non-legacy header field and the non-legacy preamble field, wherein the legacy preamble field, the legacy header field, and the non-legacy header field of the first set is generated as one stream, and the data field of the first set and the data field of the one or more second set are generated as a plurality of streams at the transmission apparatus.
 2. The reception apparatus according to claim 1, wherein the non-legacy preamble field includes a non-legacy short training field (STF) and a plurality of non-legacy channel estimation fields (CEFs), and the receiver receives, on the time axis, in order of the non-legacy STF and the plurality of non-legacy CEFs.
 3. The reception apparatus according to claim 2, wherein non-legacy header field is generated as a single carrier (SC) block or an orthogonal frequency division multiplexing (OFDM) symbol which is pre-pended by a guard interval, and a final SC block in the non-legacy header field of the first set is post-pended by a same guard interval as the pre-pended guard interval.
 4. The reception apparatus according to claim 2, wherein the data field is generated as a single carrier (SC) block or an orthogonal frequency division multiplexing (OFDM) symbol which is pre-pended by a guard interval, and a final SC block in the data field is post-pended by a same guard interval as the pre-pended guard interval.
 5. The reception apparatus according to claim 1, wherein the non-legacy header field is generated as a single carrier (SC) block or an orthogonal frequency division multiplexing (OFDM) symbol which is pre-pended by a guard interval, and the final SC block in a final non-legacy header field of the one or more second sets is post-pended by a same guard interval as the pre-pended guard interval.
 6. The transmission apparatus according to claim 3, wherein symbols in the post-pended guard interval are inverted.
 7. A reception method comprising: receiving, from a transmission apparatus, a transmission signal having an aggregate physical layer protocol data unit (aggregate PPDU) that includes a first set and one or more second sets, the first set including a plurality of first fields arranged in order of a legacy preamble field, a legacy header field, a non-legacy header field, a non-legacy preamble field, and a data field on a time axis, each of the one or more second sets including a plurality of second fields arranged in order of the non-legacy header field and the data field on the time axis; and decoding the transmission signal to generate decoded bits for the data field in the first set and the data field in the plurality of second sets by using the non-legacy header field and the non-legacy preamble field, wherein the legacy preamble field, the legacy header field, and the non-legacy header field of the first set is generated as one stream, and the data field of the first set and the data field of the one or more second set are generated as a plurality of streams at the transmission apparatus.
 8. The reception method according to claim 7, wherein the non-legacy preamble field includes a non-legacy short training field (STF) and a plurality of non-legacy channel estimation fields (CEFs), and the receiver receives, on the time axis, in order of the non-legacy STF and the plurality of non-legacy CEFs.
 9. The reception method according to claim 8, wherein non-legacy header field is generated as a single carrier (SC) block or an orthogonal frequency division multiplexing (OFDM) symbol which is pre-pended by a guard interval, and a final SC block in the non-legacy header field of the first set is post-pended by a same guard interval as the pre-pended guard interval.
 10. The reception method according to claim 8, wherein the data field is generated as a single carrier (SC) block or an orthogonal frequency division multiplexing (OFDM) symbol which is pre-pended by a guard interval, and a final SC block in the data field is post-pended by a same guard interval as the pre-pended guard interval.
 11. The reception method according to claim 7, wherein the non-legacy header field is generated as a single carrier (SC) block or an orthogonal frequency division multiplexing (OFDM) symbol which is pre-pended by a guard interval, and the final SC block in a final non-legacy header field of the one or more second sets is post-pended by a same guard interval as the pre-pended guard interval.
 12. The reception method according to claim 9, wherein symbols in the post-pended guard interval are inverted. 